CALHOUN, Ga. (FOX 5 Atlanta) - Federal investigators from the U.S. Environmental Protection Agency have determined the air quality is safe in Calhoun after setting up monitoring stations downwind of the manufacturing plant that caught fire Friday morning.

Investigators said 10 workers were inside the DHM Adhesive building around 1 a.m. when there was an explosion involving flammable chemicals.

Investigators evacuated nearby businesses and residents while federal investigators from the Environmental Protection Agency worked to determine what type of chemicals caught on fire and the environmental impact.

"So far, we haven't seen anything [in the air] it's all been zeros," said Ben Franco from the EPA.

Prior to the EPA announcement afternoon, there was a lot of uncertainty. Calhoun City Schools closed for the day and some residents FOX 5 News spoke to said they were not taking any chances.

"Putting my shirt over my mouth and nose," said resident Linda Smith.

Others were not so worried. Despite having to close for the day, one business owner across the street continued to work.

Firefighters were of course forced to remain on the scene all day, monitoring hot spots and were relieved to hear the good news.

"We are going to continue to let the chief know about our results because they will continue to be out here," said Franco.

The cause of the explosion and fire remain under investigation. Investigators said the building is a total loss.

Firefighters used more than two million gallons of water to put out the flames. EPA investigators said that water will have to be tested as well which will take several days to get those results.

"That's the next one that we will tackle - take some samples of that as well," said Franco.